SEOUL, South Korea (AP) — North Korea on Sunday revealed a few more details about a Korean-American recently sentenced to 15 years’ hard labor, saying he entered the country with a disguised identity. Pyongyang also rejected speculation that it intends to use Kenneth Bae as a bargaining chip.

In remarks carried by state media, an unidentified Foreign Ministry spokesman did not specify the Washington state man’s crimes but said he confessed. He said Bae entered North Korea “with a disguised identity in an intentional way under the back-stage manipulation of the forces hostile toward” the country.

Bae, 44, was arrested in early November in Rason, a special economic zone in North Korea’s far northeastern region bordering China and Russia, according to the North’s state media. The exact nature of Bae’s alleged crimes has not been revealed.

Friends say Bae is a devout Christian and tour operator based in China who traveled frequently to North Korea to feed orphans. Six other Americans have been detained in North Korea since 2009; they eventually were deported or released, some after trips by prominent Americans including Presidents Bill Clinton and Jimmy Carter.

The North Korean spokesman dismissed as “ridiculous and wrong” speculation by foreign media that Pyongyang intends to use Bae as a bargaining chip. He said the “generosity” the country showed in past cases “will be of no use in ending Americans’ illegal acts.”

North Korea “has no plan to invite anyone of the U.S. as regards Pae’s issue,” the spokesman said. Pyongyang refers to Bae as Pae Jun Ho, the North Korean spelling for his Korean name.

Bae’s sentencing last week came as tension remains on the Korean Peninsula following weeks of warlike rhetoric from Pyongyang and threats to attack the U.S. and South Korea. The U.S. has called for the North to grant amnesty and immediately release Bae.

The U.S. and North Korea officially remain at war because the 1950-53 Korean War ended with an armistice, not a peace treaty.